The type of dispensing package discussed herein is widely used to dispense thick cosmetic cream products to the axillae of the user. The product is extruded through one or more orifices in an applicating surface and then rubbed onto the axillae. As used herein a cosmetic cream product has a Stevens Texture Analyzer Penetration Number of 50 to 350 grams and a yield pressure of 4 to 20 grams per square centimeter as measured on a viscometer as being the highest point of a shear stress versus shear rate curve. Such dispensing packages usually have a charge of this cream product which is relatively small in comparison to the total weight of the package so the user may not realize, based upon the change in weight of the dispensing package as the product is used, when the contents have been depleted. Furthermore, the viscosity of the product prevents it from indicating when the user shakes the package, that the cream product is near depletion. Therefore, the user may unexpectedly run out of cream product and be inconvenienced by not having another package of the cosmetic product available.
One approach to this problem is given by U.S. Pat. No. 2,284,218, which issued May 26, 1942 to Livingston, wherein a projection affixed to the piston of the dispensing package protrudes through the orifice used to dispense the cream product as the elevator approaches this orifice. A projection which protrudes through the orifice may not allow ample time for the user to acquire another package of the product, since the product is exhausted by the time the signal becomes apparent. Furthermore, if the cream product is applied to the surface by contact of the applicating surface of the dispensing package with the surface, a protrusion on the dispensing package will interfere with effective application, particularly when the cream product is applied to the sensitive axilla area of the body.
It is an object of this invention to obviate the aforementioned problems related to providing indication to the consumer when the product contained within the dispensing package is nearly depleted.
It is also an object of this invention to provide a dispensing package which is easy to use, inexpensive to manufacture, and automatically provides an indication of the amount of product remaining in the dispensing package, when the product is nearly depleted.
In accordance with one aspect of the present invention there is provided a dispensing package for cream products having an interior product chamber of generally uniform cross section. The outer end of the product chamber is defined by a wall which closes the chamber and has an applicating surface to apply the product by contact. Located in the wall is an orifice which communicates with the product chamber. The bottom of the interior chamber is defined by an piston mounted generally perpendicular to the axis of the chamber and, which can move axially within the chamber, but not rotate. The periphery of the piston is generally congruent to the cross section of the interior chamber. Cantilevered from the piston is a flexible fin which is adapted to be deflected towards the orifice by means within the dispensing package. The fin will progressively move across the orifice as the piston is advanced.